This invention relates to a fuel feeding device for an internal combustion engine and more particularly to an improved fuel feeding system that assist in starting and cold warm-up.
It is well known that the fuel/air requirements of an engine vary in response to engine temperature. It has been the practice to provide some form of fuel enrichment during cold warm-up so as to insure even running of the engine and to avoid stalling. Of course, these systems are will, when the temperature is low, provide additional fuel when the engine is being cranked for starting. However, even the provision of such a cold running enrichment during starting operation will not provide adequate fuel flow to the engine so as to insure quick starting, particularly at low temperatures.
On the other hand, if the system is designed so as to provide adequate fuel for cold starting, then too much fuel will be provided to the engine during cold running and cold warm-up. That is, the temperature responsive valves proposed for cold running enrichment, if they provide adequate fuel for cold starting, will provide too much fuel once the engine has started and before it is fully warmed up.
Although devices have been provided that supply additional fuel during cranking in addition to cold running, these devices do not provide the optimum amount of fuel for both conditions. That is, these devices either supply fuel through the same fuel circuit and thus cannot offer adequate control, or supply only fuel to the engine for both cold enrichment and cold starting. As a result, it is not possible to tailor the fuel/air mixture for the engine to suit all running conditions including starting.
It is, therefore, the principal object to this invention to provide an improved arrangement for cold starting and cold running enrichment of an engine.
It is a further object to this invention to provide a cold starting and cold running enrichment system for an engine wherein the cold starting and cold running enrichments are supplied by different circuits having different controls.
It is a still further object to this invention to provide a cold starting and cold running enrichment system for an engine wherein only fuel is supplied for the cold starting operation whereas both fuel and air are mixed together and supplied for cold running enrichment.